HEALTH & THE BORDER COLLIE
© Sheila Gay
Wouldn't it be great if we didn't have to worry about any sort of canine disease? We'll probably always struggle to reach that ideal but we can be thankful that Border Collies are in general very healthy. Some years ago, the only widely available Border Collie litter test was for eyes. Dogs over 12 months old could be hip scored and adult eye tests could be done, but that was about it. To our greater advantage, times change, veterinary medicine moves on, often quite dramatically, and today there are many more tests we can do to safeguard the future health of our lovely breed.
Below you'll find information on BC health matters and testing. Please click to read my article 'DNA Testing – The Way Forward With Carriers (A Breeder's View)'.
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MEDICAL PROBLEMS THAT CAN AFFECT THE BORDER COLLIE
Even the most experienced breeder may not detect an affected puppy in the nest, especially one that is unilaterally deaf. A skilled observer might identify bilaterally deaf dogs, as they often display a lack of response to loud noises, or remain sleeping when their siblings are woken up. This is a subjective method of testing though, and is open to misinterpretation as some normal dogs may be unresponsive whilst others adapt quickly and stop reacting. A unilaterally deaf dog is very difficult to identify as it hears perfectly in the non-affected ear, and so usually behaves normally. It is virtually impossible to confirm that a dog is unilaterally deaf without a truly objective test, such as the Brainstem Auditory Evoked Response (BAER) test. In a BAER test, recording electrodes are positioned on the head, and pick up the electrical response of the brain to auditory stimuli. If the characteristic trace is acquired from both ears, the animal hears normally.
PRA – PROGRESSIVE RETINAL ATROPHY:
PRA is a degenerative disease of the photoreceptors of the eye, inherited via an autosomal recessive gene. Usually the first symptom is night-blindness, especially noticeable when the dog is in unfamiliar surroundings, but eventually the dog goes totally blind. There is no cure.
CEA – COLLIE EYE ANOMALY:
The more accurate name for it is Choroid Hypoplasia (CH) – the choroid is a layer of tissue under the retina, which in CEA can be seen to have underdeveloped, thin, almost transparent patches, in one or both eyes. Mildly affected dogs may have perfectly normal vision, but if bred from, can produce severely affected puppies. Severely affected dogs suffer a serious loss of vision and many have colobomas - holes or pits in the retina. At worst, severe CEA cases suffer intraocular haemorrhage, detachment of the retina, and blindness. CEA is inherited via an autosomal recessive gene, but thanks to the recent development of the gene test by OptiGen in the USA, producing affected puppies can be avoided in future by selective breeding.
NCL – NEURONAL CEROID LIPOFUSCINOSIS:
An hereditary, fatal disease, similar to Batten’s Disease in humans, CL is also called Storage Disease - an accumulation of toxins builds up in the brain, owing to an enzyme abnormality, which prevents the dog from disposing of them normally. Symptoms appear from around 15 months of age and gradually worsen, beginning with abnormal behaviour, such as fear of familiar people and objects, unsteadiness and abnormal gait, and progressing ultimately to dementia, disorientation, loss of bowel/bladder control, hyperactivity, rage and mania. As there is no cure, the only course is euthanasia. Confirmation of CL is post mortem. The recent development of the gene test to identify Carriers means selective breeding can eradicate this disease.
TNS – TRAPPED NEUTROPHIL SYNDROME:
An hereditary disease where the bone marrow produces white cells (known as neutrophils) but is unable to release them into the bloodstream - as a result affected puppies have an impaired immune system and will eventually die from infections which they cannot fight.
EPILEPSY - research is currently being undertaken by laboratories in various parts of the world. Please contact the Pastoral Breeds Health Foundation for more details. This foundation, supported by BC folk all over the UK, works tirelessly to promote research into health matters and in conjunction with the Border Collie Breed Council holds Open Days where testing of various kinds is available
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TESTING - WHEN CAN IT BE DONE?
A) Tests that can be performed on pups before they leave the litter:
1. Eye screening for CEA/CH (Collie Eye Anomaly/Choroidal Hypoplasia), Colobomas or other eye abnormalities
2. BAER Hearing Tests
The above 2 tests can be done from as early as 5 weeks old. A pup's hearing can be tested at any age, but the litter screening eye test should be done before pups go to their new homes. While having one or both DNA CEA/CH clear parents means a pup will not suffer that particular disease (and now that the DNA test is available, untested parents should not be bred from), it's still important to litter screen puppies, since the test should pick up any abnormalities and we can hopefully prevent other eye problems creeping into the breed.
Billy (Darian Dauntless) confidently demonstrates the BAER hearing test at 6 weeks old.
B) Tests that are performed in adulthood:
1. The adult eye test, which checks for any abnormality but particularly Progressive Retinal Atrophy and Primary Lens Luxation
2. Gonioscopy, a separate eye test which determines any predisposition to develop glaucoma
3. Hip and elbow scoring, done after the age of 12 months. The British Veterinary Association will not score the plate of a dog under 12 months, therefore an x-ray taken prior to a 1st birthday would be purely for diagnostic purposes and not admissible into the BVA/KC scheme.
This x-ray is of Darian Sundown's hips, taken in December 1988 when she was just turned 12 months old. Her score was 0:0 - very pleasing for the first pup I'd ever bred! You can see quite clearly how well the ball fits into the socket on each side.
The following links may be useful:
Eye testing panellists in the UK
The British Veterinary Association canine health schemes
BAER hearing test centres
There are 5 such tests currently available, as a result of many years of research supported by Border Collie breeders around the world. We have much to thank this dedicated group of people for. These tests can be done in adulthood, or while pups are still 'in the nest'.
CEA/CH - Collie Eye Anomaly/Choroidal Hypoplasia
NCL - Neuronal Ceroid Lipofuscinosis
TNS - Trapped Neutrophil Syndrome
MDR1 test - identifies the genetic mutation which causes an adverse reaction to certain veterinary drugs
IGS (Imerslund-Grasbeck Syndrome) - also known as Cobalamin Malabsorption or Vitamin B12 Deficiency
NCL and TNS are invariably fatal and it's hoped that in time the DNA test will result in both being totally eradicated. In the meantime however, having the DNA tests means we can identify clears, carriers and affecteds. Clears and carriers can both be bred from although obviously a carrier should only be mated to a clear. In this way no affected puppies can be produced and valuable bloodlines can be protected. The resulting puppies can then be tested to see if they have inherited the carrier parent's gene. Such knowledge is a vital tool for responsible breeders.
Testing is generally done on blood samples (the testing laboratories often prefer this), but can also be done via buccal swab and this is especially useful if a breeder needs to test pups while they're still in the nest.
The following laboratories undertake DNA testing specific to Border Collies:
OptiGen (CEA, NCL and TNS)
Laboklin or Animal Genetics UK (MDR1 & IGS)
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